Amalgamating process for recovering metals from ores.



P. KUEHN.

AMALG AMATING PROCESS FOR RECOVERING METALS FROM ORES. APPLICATION FILEDDEC- l7. I912- 1,2 31,176. Patented June 26,1917.

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PAUL KUEHN, OF DETROIT, MICHIGAN.

Specification of Letters Patent.

Patented June 26, 1917.

Application filed December 17, 1912. Serial No. 737,278.

T 0 all whom it may concern:

Be it known that 1, PAUL KmiHN, a citizen of the United States ofAmerica, residing at Detroit, in the county of Wayne and State ofMichigan, have invented certain new and useful Improvements inAmalgamating Processes for Recovering-Metals from Ores, of which thefollowing is a specification, reference being had therein to theaccompanying drawings;

This invention relates to an improved process for recovering metals fromtheir ores by amalgamation and its object is to provide a processwhereby all of the values may be recovered from comminuted ores withoutloss of mercury or interruption of the continuous operation of theprocess. My process will best be understood from a description of anapparatus by means of which it may be carried out, and one form of suchapparatus is shown in my Letters Patent of the United States dated March5, 1912 and num-' bered 1,019,054, and a further illustration is shownin the accompanying drawing, in which the figure is a, vertical sectionthrough a form of such an apparatus.

As shown in the drawing, in the bottom of a receptacle 1 of a desiredform and size, is placed a quantity of mercury 2 and a pipe or tube 3 issuspended in this receptacle with a small space between its open lowerend and the surface of the mercury. The upper end of said tube isenlarged to form a feed hopper 4 into which a pulp of finely crushed oreand a flush of water is fed in any suitable manner, the bottom of thehop per being supported slightly above the plane of the upper edge ofthe receptacle so that when the tube and receptacle are full, the

nip will have a slight head to cause it to flow over the upper edge ofthe receptacle.

When the pulp is fed into the hopper, it settles down in the tube andpassing out o the lower end thereof, rises in the receptacle andgradually overflows. In passing from the lower end of the tube throughthe nar row space between said end and the surface of the mercury, everypart of it is brought into intimate relationwith the mercury to causethe fine particles of valuable metal therein to unite with an amalgam.The pulp is caused to flow through the receptacle by the slightdiiference in height between the columns of pulp in the feed tube andreceptacle, the base of the columns being the body of mercury in themercury and form the receptacle. This difference in height is such thatthe flow will be without substantial agitation but will be sufiicient tokeep in suspension within the liquid those particles which are of lessspecific gravity than the lower end of the center column and a gentleuprising movement in the outer column, all of the values are given anopportunityto separate from the other matter and settle upon themercury, and the mercury body will not be disturbed su'liiciently tocause particles of mercury to be dislodged to any material, extent. Thisrate of flow is determined bythe head given the inner column over theouter column and its range of variation is between a minimum which isjust suflicient to keep in suspension those particles which are lighterthan the metals to be amalgamated, and a maximum which is just below thepoint at which loss of values begins.

Loss of values which is often occasioned by the fine particles ofprecious metal being carried over by the froth and light material whichfloats upon the surface of the pulp, is obviated by maintaining ahydrostatic column of pulp in the feed tube from the bottom of whichcolumn the pulp seeking its level passes over the surface of the mercuryand rises in the receptacle. All

of the froth and light matter is therefore carried downward and immersedin the water, the froth being eliminated thereby, and every particle ofprecious metal is also immersed and thus released to be precipitatedupon the mercury forming the base of the columns, the particles of lessspecific gravity than the mercury and metals amalgamating therewithbeing held in suspension in the fluid by the limited flow and floatedupwardly and over into the waste. As the pulp passes from the bottom ofthe center column, it flows radially in all directions into the bottomof the outer column of greater area, with an expanding move ment whichtends to retard its progress, and the radial movement gives an even flowthat prevents the formation of paths of flow or the mercury body, and

currents with consequent banking of sand between the paths and thecarrying over of values due to the resultant increase in flowalong thesepaths.

Leading from the bottom of the receptacle 1, preferably at its center,is an open ended pipe 5 which is extended laterally to the side of thedevice and thence upward with its open outer end 6 in the horizontalplane of the level at which it is desired to maintain the mercury in thereceptacle. In placing the mercury in the receptacle, the operator maypour it in until it begins to overflow from the end 6 of the pipe whenhe will know that it is at the exact level required, and during theoperation of the device, as amalgam is formed and the bulk of the,mercury is increased by the addition thereto of precious metal from thepulp, it will overflow from the end of said pipe, thus making theoperation continuous, as it will only be necessary for the operator to.put in more mercury from time to time through the feed tube 3 and if heputs in too. much it will not effect the operation as the surplus willsimply overflow from the pipe. The necessity for discontinuing theprocess at intervals and cleaning out the amalgam that has been formed,is obviated by thisarrangement.

Having thus fully described my invention what claim is 1. A process forrecovering metals from their ores which consists in providing a body ofmercury presenting an extended sur face, maintaining a body of ore pulpupon said mercury with a quiescent expanding flow in proximity to thesurface thereof without substantial agitation and without materiallydisturbing the. mercury body, and limiting the. flow to a ratesufficient to keep in suspension the particles contained in the pulpwhich are of less specific gravity than the metals to be recovered,whereby said metals are permittedv to separate from the pulp andamalgamate with the mercury.

2. A process for recovering metals from their. ores which consists inproviding a body of mercury presenting an extended surface, maintaininga body of ore pulp upon said mercury with a gentle flow of reducingvelocity in proximity to the surface thereof without substantialagitation of saidpulp or mercury surface, and limiting the rate of flowso as to keepfin suspension only those particles in the specificgravity-than the metals to be amalgamated.

pulp which are of less 3. A process for recovering metals from theirores which consists in providing a body ofmercury: presenting anextended surface, maintaining columns of ore pulp having a quiescentgravity flow of reducing velocity from one to another of said columnsover the surface of said body, and so limiting said iiow as, to, keep insuspension only the particles of ore pulp which are of a less specificgravity than the metals to be recovered without substantial agitation ofthe pulp or material disturbance. of the mercury,

l. A process of recovering metals from their ores which consists inproviding a body of mercury presenting an extended surface a d ma ntainig thereon c lumn f ore p lp having a quiescent expanding gravity flowfrom one to another in proximity to the surface of said body withoutmaterial disturbance of the mercury, the rapidity of such flow bei g somited; as k p in u pension in the fluid only those particles which areof less. specific gravity than the metals to, be recovered.

5,. An amalgamating process for recovering metals from their ores whichconsists in providing a body of mercury having an extended surface,maintaining columns ofv e rnlr av n a qu e c n g y ow f reducingvelocity in proximity to the surface of said body from the bottom of onecolumn to the bottom of another without substantial agitation of the,pulp or mercury, and so limiting the rapidity of said flow as to keep insuspension the particles in said pulp which are of less specific gravitythan the metal to be recovered and t0 Prevent the. carrying over ofparticles of the mercuryby h lo V 6, An amalgamating ing metals fromtheir ores which consists providing. a body of mercury, maintainingconcentric columns of ore pulp upon said body with a radial andexpanding quiescent gravity flow from the bottom of one column to thebottom of the other over the surface of said body and so; limiting thespeed of flow as to keep. in suspension within the upfiowing column onlythose particles which are of less pecific gravity than the metal to eemesam e In testimony whereof I aflix my signature in presence of twowitnesses.

PAUL KUEHN.

process for recover- Witnesses LnwIs E. FLANDERS, ANNA M Donn.

Copies of'this patent may be obtained for. five, cents each, by,addressingthe ,Gommissioner, of Patents,

Washington, I), Q.

